Macedonian prime minister Zoran Zaev, who reached the agreement with Greece’s prime minister in June, addressed the marchers in front of the EU’s office in Skopje on Sunday.

He urged citizens to grasp a historic opportunity and back the name deal, which he described as “fair”.

“The message is: We want the future, we want a European Macedonia! It is our responsibility to secure a future for our children and their children,” Mr Zaev said.

Opposition party VMRO-DPMNE staged its own rally on Sunday in the eastern town of Stip to encourage voters to reject the name change.

People marching in Skopje (Boris Grdanoski/AP)

Opposition leader Hristijan Mickoski, who has criticised the government for accepting a deal that in his view prioritises Greek interests, said, “Citizens have the right to fight until the last breath”.

Despite the forceful words, VMRO-DPMNE and the rest of Macedonia’s political opposition have advised supporters to vote according to their consciences.

Voter turnout will be a crucial factor in the referendum is crucial: 50% plus one of Macedonia’s 1.8 million registered voters must cast ballots for the referendum vote to be valid.

Opinion polls indicate the name change would be approved, but turnout could fall just short of the required threshold.

Theresa May will be met with a 132-square-metre reminder she supported Remain on her visit to Brussels on Wednesday evening after a British activist group paid for a huge advertisement in the city centre.